using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Reflection;
using NewLife.Net.Sockets;
using NewLife.Reflection;
namespace NewLife.Net.Stun
{
/// <summary>Stun服务端。Simple Traversal of UDP over NATs，NAT 的UDP简单穿越。RFC 3489</summary>
/// <remarks>
/// <a target="_blank" href="http://baike.baidu.com/view/884586.htm">STUN</a>
/// </remarks>
public class StunServer : NetServer
{
#region 属性
private IDictionary<Int32, IPEndPoint> _Public;
/// <summary>我的公网地址。因为当前服务器可能在内网中，需要调用StunClient拿公网地址</summary>
public IDictionary<Int32, IPEndPoint> Public { get { return _Public; } private set { _Public = value; } }
private IPEndPoint _Partner;
/// <summary>伙伴地址。需要改变地址时，向该伙伴地址发送信息</summary>
public IPEndPoint Partner { get { return _Partner; } set { _Partner = value; } }
private Int32 _Port2;
/// <summary>第二端口</summary>
public Int32 Port2 { get { return _Port2; } set { _Port2 = value; } }
#endregion
#region 构造
/// <summary>实例化</summary>
public StunServer()
{
Name = this.GetType().Name.TrimEnd("Server");
Port = 3478;
Port2 = Port + 1;
//// 同时两个端口
//AddServer(IPAddress.Any, 3478, ProtocolType.Udp, AddressFamily.InterNetwork);
//AddServer(IPAddress.Any, 3479, ProtocolType.Udp, AddressFamily.InterNetwork);
}
/// <summary>确保建立服务器</summary>
public override void EnsureCreateServer()
{
if (Servers.Count <= 0)
{
// 同时两个端口
AddServer(IPAddress.Any, Port, ProtocolType.Unknown, AddressFamily.InterNetwork);
AddServer(IPAddress.Any, Port2, ProtocolType.Unknown, AddressFamily.InterNetwork);
var dic = new Dictionary<Int32, IPEndPoint>();
IPEndPoint ep = null;
var pub = NetHelper.MyIP();
StunResult rs = null;
WriteLog("获取公网地址……");
foreach (var item in Servers)
{
if (item.Local.ProtocolType == ProtocolType.Tcp) continue;
// 查询公网地址和网络类型，如果是受限网络，或者对称网络，则采用本地端口，因此此时只能依赖端口映射，将来这里可以考虑操作UPnP
if (rs == null)
{
item.Start();
rs = new StunClient(item).Query();
if (rs != null)
{
if (rs != null && rs.Type == StunNetType.Blocked && rs.Public != null) rs.Type = StunNetType.Symmetric;
WriteLog("网络类型：{0} {1}", rs.Type, rs.Type.GetDescription());
ep = rs.Public;
if (ep != null) pub = ep.Address;
}
}
else
ep = new StunClient(item).GetPublic();
if (rs != null && rs.Type > StunNetType.AddressRestrictedCone) ep = new IPEndPoint(pub, item.Port);
WriteLog("{0}的公网地址：{1}", item.Local, ep);
dic.Add(item.Port, ep);
}
// Tcp没办法获取公网地址，只能通过Udp获取到的公网地址加上端口形成，所以如果要使用Tcp，服务器必须拥有独立公网地址
foreach (var item in Servers)
{
if (item.Local.ProtocolType != ProtocolType.Tcp) continue;
ep = new IPEndPoint(pub, item.Port);
WriteLog("{0}的公网地址：{1}", item.Local, ep);
dic.Add(item.Port + 100000, ep);
}
//var ep = StunClient.GetPublic(Port, 2000);
//WriteLog("端口{0}的公网地址：{1}", Port, ep);
//dic.Add(Port, ep);
//ep = StunClient.GetPublic(Port2, 2000);
//WriteLog("端口{0}的公网地址：{1}", Port2, ep);
//dic.Add(Port2, ep);
WriteLog("成功获取公网地址！");
Public = dic;
}
}
#endregion
#region 方法
/// <summary>接收到数据时</summary>
/// <param name="session"></param>
/// <param name="stream"></param>
protected override void OnReceive(ISocketSession session, Stream stream)
{
if (stream.Length > 0)
{
var remote = session.Remote;
//if (remote == null && session != null) remote = session.RemoteEndPoint;
var request = StunMessage.Read(stream);
WriteLog("{0} {1} {2}{3}", request.Type, remote, request.ChangeIP ? " ChangeIP" : "", request.ChangePort ? " ChangePort" : "");
// 如果是兄弟服务器发过来的，修正响应地址
switch (request.Type)
{
case StunMessageType.BindingRequest:
//case StunMessageType.BindingResponse:
request.Type = StunMessageType.BindingRequest;
if (request.ResponseAddress != null) remote.EndPoint = request.ResponseAddress;
break;
case StunMessageType.SharedSecretRequest:
//case StunMessageType.SharedSecretResponse:
request.Type = StunMessageType.SharedSecretRequest;
if (request.ResponseAddress != null) remote.EndPoint = request.ResponseAddress;
break;
default:
break;
}
// 是否需要发给伙伴
if (request.ChangeIP)
{
//if (Partner != null && !Partner.Equals(session.Host.LocalEndPoint.GetRelativeEndPoint(Partner.Address)))
//{
// // 发给伙伴
// request.ChangeIP = false;
// // 记住对方的地址
// request.ResponseAddress = remote.EndPoint;
// //session.Send(request.GetStream(), Partner);
// var us = session.Host as UdpServer;
// if (us != null)
// {
// //us.CreateSession(Partner).Send(request.GetStream());
// us.Send(request.GetStream(), Partner);
// }
// return;
//}
// 如果没有伙伴地址，采用不同端口代替
request.ChangePort = true;
}
// 开始分流处理
switch (request.Type)
{
case StunMessageType.BindingRequest:
//case StunMessageType.BindingResponse:
OnBind(request, session);
break;
case StunMessageType.SharedSecretRequest:
break;
default:
break;
}
}
}
#endregion
#region 绑定
/// <summary>绑定</summary>
/// <param name="request"></param>
/// <param name="session"></param>
/// <returns></returns>
protected void OnBind(StunMessage request, ISocketSession session)
{
var rs = new StunMessage();
rs.Type = StunMessageType.BindingResponse;
rs.TransactionID = request.TransactionID.ReadBytes();
rs.MappedAddress = session.Remote.EndPoint;
//rs.SourceAddress = session.GetRelativeEndPoint(remote.Address);
if (Public != null)
{
if (session.Local.ProtocolType == ProtocolType.Tcp)
rs.SourceAddress = Public[session.Port + 100000];
else
rs.SourceAddress = Public[session.Port];
}
// 找另一个
ISocketSession session2 = null;
Int32 anotherPort = 0;
for (int i = 0; i < Servers.Count; i++)
{
var server = Servers[i];
if (server.Local.ProtocolType == session.Local.ProtocolType && server.Local.Port != session.Local.Port)
{
anotherPort = server.Port;
if (server.Local.ProtocolType == ProtocolType.Tcp)
{
break;
}
else
{
session2 = (server as UdpServer).CreateSession(session.Remote.EndPoint);
if (session2 != null) break;
}
}
}
//rs.ChangedAddress = Partner ?? session2.GetRelativeEndPoint(remote.Address);
if (Public != null)
{
if (session.Local.ProtocolType == ProtocolType.Tcp)
rs.ChangedAddress = Partner ?? Public[anotherPort + 100000];
else
rs.ChangedAddress = Partner ?? Public[anotherPort];
}
String name = Name;
if (name == this.GetType().Name) name = this.GetType().FullName;
rs.ServerName = String.Format("{0} v{1}", name, AssemblyX.Create(Assembly.GetExecutingAssembly()).CompileVersion);
// 换成另一个
if (request.ChangePort) session = session2;
session.Send(rs.GetStream());
}
#endregion
#region 辅助
static Boolean IsResponse(StunMessageType type)
{
return ((UInt16)type & 0x0100) != 0;
}
#endregion
}
}
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